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What Is Healthy Soil? | Earth Wise

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Soil supports life by providing many critical ecosystem services.  For example, soil acts as a water filter, a growing medium, and provides habitat for billions of organisms.  Soil is also the foundation of our cities and towns, and the basis of global agroecosystems, which provide humans with feed, fiber, food, and fuel.

For all of these reasons and many more, having healthy soil is vital.  But what does soil health mean? And how should it be measured?

According to new analysis by researchers from Cranfield University and Nottingham University in the U.K., how we think about, measure, and study soil must change in order to better understand how to manage this resource effectively. 

While the term ‘soil health’ is widely used, it means different things to different people.  There is no single agreed upon way to gauge the overall health of soil. 

Current approaches to assess soil health measure individual soil properties and use findings  to assign a single number giving an overall score.  But according to the research team, this does not reflect the wider system perspective that’s needed to fully evaluate the health of soil over time.

Instead, the researchers propose a new system to assess soil health based on a hierarchical framework that takes in several measures, including signs of life, signs of function, signs of complexity, and signs of emergence, which is the extent to which soils recover from multiple stressors. 

This new approach, which can be applied to all soils, moves us closer to an interdisciplinary understanding of the whole picture of soil health.  After all, healthy soil is fundamental to our survival.

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We need to change how we think about soil

Photo, posted April 8, 2008, courtesy of Brian Boucheron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Unhealthy Air | Earth Wise

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According to the World Health Organization, almost the entire global population – 99% in fact – breathes air that exceeds WHO air quality limits and threatens their health.

Air quality is of great concern everywhere.  Over 6,000 cities in 117 countries monitor air quality, but the people living in those cities are still breathing unhealthy levels of fine particulate matter and nitrogen dioxide. The WHO is citing these findings as a compelling reason to curb fossil fuel use and to take other steps to reduce air pollution levels. 

There is growing number of studies of the damage air pollution does to the human body.  Even low levels of many air pollutants can cause significant harm.  Particulate matter – especially so-called PM2.5 – is capable of penetrating deep into the lungs and entering the bloodstream, contributing to cardiovascular, cerebrovascular, and respiratory problems. 

Nitrogen dioxide is associated with respiratory diseases – especially asthma – and leads to respiratory symptoms, hospital admissions, and visits to emergency rooms.

The WHO is calling to governments around the world to take additional steps to improve air quality including adopting stricter air quality standards, supporting the transition to clean household energy sources, implementing stricter vehicle emission standards, reducing the use of incineration, and many other actions.

According to the WHO, cities in high-income countries fare better in terms of air quality, but very few places avoid unhealthy air entirely.   Seven million deaths a year are linked to unhealthy air quality.  It is a global crisis that cannot be ignored.

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Billions of people still breathe unhealthy air: new WHO data

Photo, posted December 1, 2021, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

River Of Dust | Earth Wise               

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Every year, more than 100 million tons of dust blow out of North Africa.  Strong seasonal winds lift the dust from the Sahara Desert northward.  A few times a year, the winds from the south are strong and persistent enough to drive the dust all the way to Europe.

On March 15, a large plume of Saharan dust blew out of North Africa and crossed the Mediterranean into Western Europe.  European cities were blanketed with the dust, degrading their air quality, and turning skies orange.  Alpine ski slopes were stained with the dust.

These dust events are associated with so-called atmospheric rivers that arise from storms.  Such rivers usually bring extreme moisture but can also carry dust.  Over the past 40 years, nearly 80% of atmospheric rivers over northwestern Africa have led to extreme dust events over Europe.  The March 15 event was associated with Storm Celia, a powerful system that brought strong winds, rain, sleet, hail, and snow to the Canary Islands.

Atmospheric dust plays a major role in climate and biological systems.  The dust absorbs and reflects solar energy and also fertilizes ocean ecosystems with iron and other minerals.

The climate effects of dust are complicated.  Dust can decrease the amount of sunlight reaching the surface, affect cloud formation, and decrease temperatures.  But dust also darkens the snowpack, leading to more rapid snowmelt.  A 2021 dust event resulted in a rapid melt of Alpine snow, reducing its depth by half in less than a month.

The effects of this year’s dust event are not yet known, but this atmospheric river associated with Storm Celia appeared to carry less water and more dust compared with the 2021 event.

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An Atmospheric River of Dust

Photo, posted December 2, 2019, courtesy of Catherine Poh Huay Tan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And The Winter Olympics | Earth Wise

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According to a new study led by researchers from the University of Waterloo in Canada, climate change will limit where the Winter Olympics can be held as winter changes across the Northern Hemisphere. 

The international research team found that by the end of the century only one of the 21 cities that have previously hosted the Winter Olympics would be able to reliably provide fair and safe conditions for winter sports if global greenhouse gas emissions are not dramatically reduced. 

However, if the emissions targets set forth in the Paris Climate Agreement can be reached, the number of climate-reliable host cities for the Winter Olympics would jump to eight.

In the study, which was recently published in the journal Current Issues in Tourism, the researchers reviewed historical climate data from the 1920s to today, as well as future climate change scenarios for the 2050s and 2080s.  The researchers also surveyed international athletes and coaches, and found that 89% of them felt that changing weather patterns are already affecting competition conditions. 

The average February daytime temperature of host cities has been steadily increasing.  At the winter games held between the 1920s and 1950s, the average temperature was 32.7°F.  It rose to 37.6°F at games between the 1960s and 1990s, and has spiked to 43.3°F in the games held in the twenty-first century.  The planet is projected to warm another 3.6°F to 7.9°F this century depending on our ability to mitigate greenhouse gas emissions.

Reducing global greenhouse gas emissions is critical to ensure that there remain places across the globe to host the Winter Olympics.

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Climate change threatens future Winter Olympics

Photo, posted February 21, 2010, courtesy of Michael via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Homes In The Netherlands | Earth Wise

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The Netherlands is a country that is largely built on reclaimed land and a third of it remains below sea level.  The Dutch have long experience with dealing with rising waters.  The city of Amsterdam has almost 3,000 houseboats in its canals.

As sea levels continue to rise across the globe, it is no surprise that the Dutch have taken the lead in creating communities composed of floating houses and buildings.

A floating house is a structure fixed to the shore, often resting on steel poles, and usually connected to the local sewer system and power grid.  They are much like ordinary houses except that instead of a basement, they have a concrete hull that acts as a counterweight, allowing them to remain stable in the water.

The ones in the Netherlands are often prefabricated, square-shaped, three-story townhouses.  Rotterdam, which is 90% below sea level, is home to the world’s largest floating office building as well as a floating farm.

Floating buildings have their challenges, not the least of which are the effects of severe wind and rainstorms, or even the passing of large ships which can make the buildings rock.  Infrastructure like electricity and sewer service is not that simple to implement for the buildings.  But the benefits of floating buildings may outweigh the costs.

For cities facing worsening floods and a shortage of buildable land, floating homes are a potential solution for expanding urban housing in the age of climate change.  Dutch engineers are spearheading floating building projects in Britain, France, and Norway, as well as in threatened island locations like French Polynesia and the Maldives.

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Embracing a Wetter Future, the Dutch Turn to Floating Homes

Photo, posted May 23, 2007, courtesy of Jeff Hutchison via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Nanoplastics In The Air | Earth Wise

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The world is awash in plastic.  Discarded plastic litters our roadways, woodlands, and beaches.  It piles up in landfills.  Plastic enters the oceans by the millions of tons.  And plastic is finding its way even to remote and supposedly pristine parts of the world.

A team of researchers has found nanoplastics at the isolated high-altitude Sonnblick Observatory in the Austrian Alps.  This is the first time the particles were found in the area.  The researchers were looking for certain organic particles and only found the nanoplastics by chance.

The detected plastic particles were less than 200 nanometers in size, about one hundredth the width of a human hair.  It is highly unlikely that such particles originated in remote Alpine areas.

The researchers were looking for organic particles by taking samples of snow or ice, evaporating them, and then burning the residue to detect and analyze the vapors.  They described the detection method as essentially like a mechanical nose.  In this case, the nose smelled burning plastics in the form of polypropylene and polyethylene terephthalate.

Looking into the issue, the researchers found a strong correlation between high concentrations of nanoplastics and winds coming from the direction of major European cities – especially Frankfurt and the industrial Ruhr area of Germany, but also the Netherlands, Paris, and even London.

Modeling supports the idea that nanoplastics are transported by air from distant urban places.  This is particularly worrisome because it means that there are likely hotspots of nanoplastics in our cities and in the air that we are breathing.  Plastics appear to be everywhere.

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Nanoplastics found in the Alps, transported by air from Frankfurt, Paris and London

Photo, posted July 1, 2013, courtesy of Robert J. Heath via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Decarbonizing The Most Polluting Heavy Industries | Earth Wise

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The production of steel, cement, and ammonia accounts for about 20% of the carbon dioxide humans pour into the atmosphere.  Modern cities are largely constructed from concrete and steel and most of our food is grown using fertilizer made from ammonia. 

The most widely discussed solutions to decarbonizing these industries are green hydrogen and carbon capture and storage or CCS.

Steel manufacture is responsible for 11% of society’s emissions.  Most production starts by burning coal in a blast furnace. Using CCS could reduce emissions from burning the coal.  But the blast furnace could be eliminated entirely by the use of electrolysis to produce the pure iron needed to make steel.  This would be extremely energy-intensive but using a low-carbon source like green hydrogen could greatly reduce the emissions from making steel.

Ammonia is made by producing hydrogen from natural gas and then combining it with atmospheric nitrogen.  Both the hydrogen production and ammonia synthesis are energy intensive.  Using green hydrogen would eliminate emissions from the hydrogen production itself and new research on catalysts aims at lower-temperature, less-energy intensive ammonia synthesis.

Decarbonizing cement manufacturing is perhaps the toughest challenge.  Cement is made in a high-temperature kiln, typically heated by burning fossil fuels.  The process converts calcium carbonate and clay into a hard solid called clinker.  The main byproduct of that is even more carbon dioxide.  Burning green hydrogen and capturing carbon emission are about the best hope for reducing cement manufacturing emissions.

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Can the World’s Most Polluting Heavy Industries Decarbonize?

Photo, posted June 30, 2009, courtesy of Portland Bolt via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Deadly Urban Heat On The Rise | Earth Wise

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According to a new study by the Columbia Climate School, exposure to deadly urban heat has tripled since the 1980s.  The increase is the combined result of both rising global temperatures and booming urban population growth.

The study looked at more than 13,000 cities worldwide and found that incidents of extreme heat and humidity have increased dramatically.   It defined extreme heat as 30 degrees Celsius on the wet-bulb temperature scale that takes into account the effect of high humidity.  In 1983, there were 40 billion person-days under such conditions.  By 2016, the number was 119 billion.  More specifically, in 2016 1.7 billion people were subjected to such conditions on multiple days.

Sheer urban population growth accounted for two-thirds of the increase, while actual warming contributed a third.  Over recent decades, hundreds of millions of people have moved from rural areas to cities, which now hold more than half the world’s population.  And because of the urban heat island effect, temperatures in cities are generally higher than in the countryside.

In the United States, about 40 sizable cities have seen rapidly growing exposure to extreme heat, mainly clustered in Texas and the Gulf Coast.  Globally, nearly a quarter of the world’s population is affected by the increased incidence of extreme temperatures.

A study last year showed that combinations of heat and humidity literally beyond the limits of outdoor human survival have been popping up around the world.  A wet-bulb temperature reading of 30 – equivalent to 106 degrees Fahrenheit on the “real feel” heat index – is the point at which even most healthy people find it hard to function outside for long, and the unhealthy might become very ill or even die.

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Exposure to Deadly Urban Heat Worldwide Has Tripled in Recent Decades, Says Study

Photo, posted March 5, 2007, courtesy of Michael Phillips via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wastewater As A Freshwater Source | Earth Wise

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Water covers three-quarters of our planet, but freshwater – the water we drink, bathe in, and irrigate crops with – comprises only 3% of the world’s water and much of that is frozen in glaciers or otherwise unavailable.  Nearly 3 billion people suffer from water scarcity for at least some of the year.

Natural freshwater sources – lakes, rivers, and groundwater – are under stress from the effects of climate change and from the increasing demands of city populations.  The wastewater treatment plants in large cities represent a significant potential water source provided that sustainable and economical technologies to produce it can be developed.

Researchers at Lehigh University in Pennsylvania have patented an innovative ion exchange desalination process that is a legitimate candidate to transform wastewater into usable water.

Existing large-scale desalination systems make use of semipermeable reverse osmosis membranes that require an energy source to run the system.  The Lehigh process, which they call HIX-Desal, harnesses the unique chemistry of carbon dioxide to take the place of the energy used in reverse osmosis systems. 

Tests of the new system show that the salinity of treated wastewater can be reduced by more than 60% by the HIX-Desal process without requiring any reverse osmosis.  At an Allentown, Pennsylvania water treatment plant where the system was tested, the researchers estimated that using the system could save about a million kWh per day in electricity usage, enough energy to power 94 homes for a year.

With this system, waste carbon dioxide from landfills or turbine exhaust can be used to desalinate municipal wastewater.  It could be the basis of a circular economy.

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Desalination tech uses CO2 to tap into municipal wastewater as alternative freshwater source

Photo, posted November 28, 2020, courtesy of Richard Ricciardi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon From 25 Cities | Earth Wise

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There are roughly 10,000 cities in the world, defined as places with at least 50,000 inhabitants with a sufficient population density.  Roughly half the world’s population lives in cities.

Urban carbon emissions are one of the world’s biggest problems with respect to the climate.  A new study has determined that just 25 cities globally are responsible for 52% of urban greenhouse gas emissions.

The study gathered data on greenhouse gas emissions in 167 cities in 53 countries.  The results were that megacities in Asia, such as Shanghai and Tokyo, were among the biggest total emitters, and that major cities in Europe, the US, and Australia tended to have larger per capita emissions.  Several Chinese cities, however, matched levels seen in developed countries.  Researchers tracked emissions over time in 42 of the cities studied.  Some cities saw declining emissions in the period between 2005 and 2016.  These included Oslo, Houston, Seattle, and Bogota.  Others saw large increases, including Rio de Janeiro, Johannesburg, and Venice.

The largest sources of emissions are power generation, industry, and transportation.  In a third of the cities, road transportation alone accounted for over 30% of emissions.  (Railways, waterways, and aviation combined only accounted for less than 15% of total emissions).

Half of the world’s population lives in cities, but cities are responsible for more than 70% of greenhouse gas emissions.  Thus, cities have a big responsibility for the decarbonization of the global economy.  Of the 167 cities in the study, 113 have set emission-reduction targets.  But as the study shows, cities have much more work to do to meet the goals of the Paris Climate Agreement.

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Two Dozen Large Cities Produce 52 Percent of Urban Carbon Emissions

Photo, posted December 1, 2017, courtesy of Hector Galbis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Soaring Heat And Inner-City Neighborhoods | Earth Wise

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The record-breaking heatwaves this summer have exposed the special vulnerability inner cities have to the effects of summer heat.  Climate change has exacerbated and supercharged heatwaves, as was seen in Seattle and Portland in late June.

Urban cores can be 10 degrees or more warmer than the surrounding countryside.  The urban heat island effect is a result of how cities are built, with so much pavement, so many buildings, and not enough trees.  On top of this, decades of disinvestment in neighborhoods where people of color live have left them especially vulnerable to heat as their homes are not able to cope with it.

In New York City, some residents of Hunts Point in the Bronx keep lists of neighbors they check on to help keep the most vulnerable alive during heat waves.  The city has subsidized 74,000 air conditioners for low-income, elderly residents, and is spending millions to plant trees.  In Phoenix, the hottest big city in the country, officials are working to develop new models for cooler public housing and cooling for streets and pedestrian corridors.

A study, published in 2020, looked at the linkage between higher heat island temperatures and past practices of redlining, where home loans and insurance were unavailable to people in neighborhoods of color.  In 94 of 108 communities studied, the formerly redlined neighborhoods had higher surface temperatures.

Cities are confronted with two heat problems:  emergencies that require immediate action to save lives, and long-term issues related to combating soaring temperatures in heat islands strengthened by global warming. In many cases, cities are not prepared for either problem.  Dealing with and adapting to heat is essential to the long-term viability and quality of life in our cities.

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A Triple Whammy Has Left Many Inner-City Neighborhoods Highly Vulnerable to Soaring Temperatures

Photo, posted May 27, 2014, courtesy of Dan DeLuca via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Is Peak Oil Here? | Earth Wise

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For many years there has been talk of “peak oil”, the point at which rising world oil consumption would peak and then start declining.  Some analysts have been predicting that this could happen by the 2030s.   But the coronavirus pandemic drove a 9% slump in oil demand in 2020 that some economists are saying might never be entirely reversed.

There are three major forces driving down the world’s appetite for oil:  decarbonization of economies to meet the goals of the Paris climate agreement, declining demand for oil as renewable energy sources and electric vehicles are increasingly adopted, and detoxification as cities act to curb particulates and emissions from burning petroleum.

The largest single factor is electric vehicles.  Automobiles currently consume almost half of the world’s oil.  As of the end of 2020, there were an estimated 10 million electric cars as well as more than 600,000 electric buses and trucks.  This is still less than 1% of all vehicles, but 5% of all new cars being bought are now electric and the number is growing rapidly.  Experts estimate that nearly a quarter of global car sales will be electric vehicles by 2025 and many car manufacturers are promising to sell only electric cars within the next 10 years.

The decline in oil demand is pretty much inevitable at this point.  The main question is how quickly it will happen.  Road transport makes up 48% of global oil demand, petrochemicals account for 14%, aviation 7%, and shipping 6%.  Ultimately all these things are likely to diminish over time. 

Only time will tell, but the long-awaited arrival of peak oil may already have happened.

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Amid Troubles for Fossil Fuels, Has the Era of ‘Peak Oil’ Arrived?

Photo, posted April 14, 2019, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Importance Of Urban Green Spaces | Earth Wise

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Projections are that 68% of the global population will be living in cities by 2050.  It is therefore not surprising that urban green spaces are critically important for promoting mental and physical well-being.

An international study, published in Science Advances, took soil samples from different types of urban green spaces and comparable neighboring natural ecosystems in 56 cities from 17 countries across six continents.

The study concluded that even roadside plantings contribute a range of important microbial communities that are critical for sustaining productive ecosystems services, such as filtering pollutants and sequestering carbon dioxide.

Parks and gardens constitute most of the open spaces available for recreational activities in cities and play important roles in curbing pollution, reducing noise, and lowering air temperatures.

In addition, human exposure to soil microbes has been shown to be beneficial to human health by promoting effective immunoregulation functions and reducing allergies. The study found that city parks and even roadside plantings support a great variety of different microbes that are different from natural ecosystems. 

We think of roadsides as being barren but the vegetation along footpaths and roadsides are important microbial habitats.  Some European cities, such as Bern in Switzerland, have instituted policies to protect the natural vegetation along footpaths and roadsides.

The new study is a part of a series of research efforts looking at the important of green spaces for ecosystem health.  As the world becomes increasingly urbanized, every bit of greenery in cities and highways is important and is needed for sustaining a healthy environment.

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Every spot of urban green space counts

Photo, posted June 3, 2013, courtesy of Manuel MV via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Hottest June | Earth Wise

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A series of heatwaves from coast to coast caused June 2021 to be the hottest June on record in the U.S. The average June temperature across the contiguous U.S. was 72.6 degrees Fahrenheit, making it the hottest June in 127 years of record keeping and breaking the previous record set in 2016 by nearly a full degree. Eight states had their hottest June on record and six others marked their second hottest June.

One of the most extreme heatwaves in modern history impacted the Pacific Northwest of the U.S. and western Canada late in the month.  Temperature records were not merely broken in the region; they were smashed over an incredibly hot four-day period from June 26th through June 29th when all-time records over 100 degrees were set at dozens of locations.

Portland, Oregon’s average high temperature over this period was 112 degrees, breaking the previous 3-day record by an amazing 6 degrees.  The high on June 28th was 116 degrees, an all-time record for the city.  Seattle set back-to-back all-time heat records of 104 on June 27th and then 108 on June 28th.  In the previous 126 years, Seattle had only hit 100 degrees three times.  It reached that mark 3 days in a row in June.

Crossing the border, the town of Lytton, British Columbia reached a temperature of 121 degrees on June 29th, the third day in a row in which the town registered a new all-time high temperature ever measured in Canada.  To put this in perspective, this temperature is hotter than has ever been recorded in Las Vegas.

June was a hot month indeed.

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June 2021 was the hottest June on record for U.S.

Astounding heat obliterates all-time records across the Pacific Northwest and Western Canada in June 2021

Photo, posted July 7, 2021, courtesy of Poyson / GPA Photo Archive via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Strategies To Cool Off Cities | Earth Wise

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Heatwaves in cities are becoming increasingly common and increasingly intense.  The warming climate is a big factor, but it is the nature of our cities that really drives up temperatures.  Solar radiation stored throughout the day on asphalt and buildings is released slowly during the night, which generates significant heat stress.

A study carried out by a major Barcelona university and published in the journal Urban Climate looked at the effectiveness of various ways to mitigate the heating effects in cities.  In particular, the study examined the effects of the use of white roofs on buildings and the expansion of urban green areas with daily irrigation in the Barcelona metropolitan area.  It simulated various scenarios incorporating combinations of these two mitigation strategies.

The strategy with the greatest impact was a combination of the use of both white roofs and the addition of six urban parks, which is a target set by the Barcelona Urban Master Plan.  This scenario resulted in an average temperature reduction of 2.25 degrees Fahrenheit.  The maximum reduction occurs during the mid-afternoon with a reduction of 7 degrees and the combination still provides more than 3 degrees of reduction at 9 pm.  Reducing temperatures this way also results in a reduction in energy consumption, with 26% less spending on air conditioning.

The 2-pronged strategy combines the benefits of reducing the temperature at night due to more urban green areas with the reduction of daytime heat due to both the increased reflectivity of white roofs as well as the irrigation of the green areas.

The study demonstrates how modeling efforts can help urban planners to counteract the impacts of heatwaves, which are likely to increase with climate change and intensification of urbanization.

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White roofs and more green areas would mitigate the effects of heat waves in cities

Photo, posted January 16, 2011, courtesy of Sean MacEntee via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Deep Learning And Dirty Air | Earth Wise

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Poor air quality is a major global problem.  According to the World Health Organization, exposure to air pollution is linked to the premature deaths of an estimated seven million people every year.  In fact, 9 out of 10 people breathe air that contains more pollutants than what the WHO considers safe.  Air pollution is the fourth largest threat to human health, trailing only high blood pressure, dietary risks, and smoking.

But predicting pollution levels at a given place and time remains challenging.  According to a new study recently published in the journal Science of the Total Environment, scientists are turning to deep learning to improve air quality estimates. 

According to researchers, satellite observations and ground observations both measure air pollution, but both have major limitations.  For example, satellites may collect data at the same time and at the same location each day, but they miss how emissions may vary throughout the day.  Ground-based observations from weather stations do continuously collect data, but they only do so in a limited number of locations.    

As a result, scientists have turned to deep learning – a type of machine learning – to analyze the relationship between satellite and ground-based observations of nitrogen dioxide around Los Angeles.  Nitrogen dioxide is associated with emissions from traffic and power plants.  The researchers were able to rely on the learned relationship to take daily satellite observations and create hourly estimates of atmospheric nitrogen dioxide levels in approximately three mile grids.     

According to the research team, this study could be repeated for other greenhouse gases, and applied to different cities and regions – or even whole continents. 

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Scientists turn to deep learning to improve air quality forecasts

Air Pollution

Photo, posted November 4, 2019, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Residential Gardens And Pollinators | Earth Wise

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A new study led by the University of Bristol in the UK measured for the first time how much nectar is produced in urban areas to gauge the role of residential gardens in providing nutrients for pollinators.  They discovered that home gardens accounted for the vast majority of the crucial nutrients for pollinators; in fact, some 85% on average.

The study found that gardens generated a daily average of about a teaspoon of the unique sugar-rich liquid found in flowers which pollinators drink for energy.  A teaspoon sounds like very little, but it is enough to feed thousands of bees.

The research examined nectar production in four major UK towns and cities and measured nectar production in nearly 200 species of plants.  The results were that the nectar supply in urban landscapes is more diverse than in farmland and nature reserves.   In addition, gardens are critical because they produce the most nectar per unit area of land and actually cover the largest area of land in the cities studied.  In those cities, nearly a third of the land comprised domestic gardens, which is six times the area of parks and 40 times the area of small green allotments.

The upshot of the research is that home gardeners have a huge role to play in pollinator conservation.  Without domestic gardens, there would be far less food for pollinators that include bees, wasps, butterflies, moths, flies, and beetles.  Thus, it is important for home gardeners to keep planting nectar-rich flowers, mow lawns less often to let dandelions, clovers, and daisies flourish, avoid harmful pesticides, and avoid covering gardens in paving, decking, or artificial turf.

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Pioneering research reveals gardens are secret powerhouse for pollinators

Photo, posted June 23, 2018, courtesy of Wolfferl via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Compost And Landfills | Earth Wise

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Composting is popular as a way to keep solid waste out of landfills and many people turn much of their kitchen waste into rich soil amendments.   Cities and towns across the country have composting programs that collect waste from residents to produce large quantities of compost rather than adding the waste to landfills.  A new study from North Carolina State University looked into the environmental benefits of actually using compost at landfills.

Most municipal composting programs require that the compost they produce gets used “beneficially”.  The new research shows that using compost as an alternative daily cover at landfills is competitive and often superior to the use of compost as a soil amendment in terms of its environmental benefits.

Landfills apply a layer of daily cover to reduce odors, reduce windblown debris, and keep vermin out of landfill waste.  Federal regulations require six inches of soil as a daily cover.

Compost from food waste in particular is not always suitable for soil amendment in gardens and agricultural fields because it often contains broken glass and other contaminants.

The North Carolina State study looked at the environmental impact of using compost as daily cover in landfills compared with its use as a soil amendment.  They looked at global warming potential, acidification potential, eutrophication (which is the amount of nutrients released to ground and surface water), cumulative energy demand, and the depletion of resources.

The study concluded that using compost as landfill daily cover is environmentally superior with regard to eutrophication, acidification, and global warming potential.  On the other hand, soil amendment was better in terms of resource depletion and cumulative energy demand.

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Applying Compost to Landfills Could Have Environmental Benefits

Photo, posted April 22, 2008, courtesy of Alachua County via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Pandemic Lockdowns And Carbon Emissions | Earth Wise

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The early months of the COVID-19 pandemic saw many human activities reduced to a fraction of what they were previously.  Notably, air pollution in major cities was dramatically lower than it had been in decades.  Now, a new study has looked at the effect of the pandemic shutdowns on carbon dioxide emissions.

An international team of climate scientists has published an assessment of carbon dioxide emissions by industry, transportation, and other sectors from January through June.  According to their measurements, this year’s pandemic lockdowns resulted in a 9% decline in emissions from 2019 levels.

An earlier study reported a 17% drop in CO2 emissions, but the new study was more comprehensive and detailed.

The new data includes estimates of day-by-day, sector-specific and country-level differences in CO2 emissions derived from frequently updated data sources, some of which are nearly in real-time.  It tracks the effects of COVID-19-related disruptions of human activities in China starting in February and in the United States and Europe in March through May.

The data revealed the resumption of emissions in many regions, such as in China, where they are now back to pre-pandemic levels.  Emissions in the Americas and Europe have been slower to recover, especially in the US, where COVID-19 hotspots are continuing to emerge. 

The reduction in carbon emissions has been due mostly to transportation with fewer people driving to work and traveling by air.  Even by June, when lockdowns were easing, global emissions were still significantly reduced.  In any case, a pandemic is a highly undesirable and unwelcome way to reduce carbon emissions, but the data from this year does show that it is effective.

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Pandemic lockdowns caused steep and lasting carbon dioxide decline

Photo, posted August 7, 2020, courtesy of Michael Mueller via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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